eliminate WHO arguments from interpreter-private functions * interpreter-private.h, inpterpreter-private.cc (__get_interpreter__, __get_dynamic_loader__, __get_error_system__, __get_gh_manager__, __get_help_system__, __get_input_system__, __get_load_path__, __get_load_save_system__, __get_event_manager__, __get_output_system__, __get_type_info__, __get_symbol_table__, __get_current_scope__, __require_current_scope__, __get_evaluator__, __get_bp_table__, __get_child_list__, __get_cdef_manager__, __get_display_info__, __get_gtk_manager__): Eliminate WHO argument. Previously, it was never displayed by __get_interpreter__. And, as pointed out by Petter Tomner in patch #10216, passing a std::string object could have performance issues. (__get_interpreter__): Eliminate useless call to error. Display message to std::cerr then abort.

--- a/libinterp/octave-value/ov-classdef.cc	Tue Jun 21 15:44:03 2022 +0200
+++ b/libinterp/octave-value/ov-classdef.cc	Wed Jun 22 12:48:59 2022 -0400
@@ -255,7 +255,7 @@
 
           // Temporarily set lvalue list of current statement to NULL, to avoid
           // using that list for the execution of the method "numel"
-          octave::interpreter& interp = octave::__get_interpreter__ ("octave_classdef::xnumel");
+          octave::interpreter& interp = octave::__get_interpreter__ ();
           octave::tree_evaluator& tw = interp.get_evaluator();
 
           octave::unwind_action act ([&tw] (const std::list<octave::octave_lvalue> *lvl)